I am studying in the New Jersey, US (which is where I live) and the school I am going with won't allow students to just "solo" even if their instructor says they are ready ...
They have a rule that you have to pass a checkride (stage check ... whatever).
The bottom line is that I have to pass a written (school issued), an oral with a senior instructor (other than my own) and pass the practical test with that same senior instructor (practical test that consists in every flight manouver except for short and soft field landings and takeoffs).
To make a long story short ... I have been taking lessons for about 2 1/2 months and i have about 23 hours ... and I have yet to solo. If everything goes well I should be able to do it in a couple of weeks ... if everything goes well...